skip to main content

Title: On the stability and compressive nonlinearity of a physiologically based model of the cochlea

Hearing relies on a series of coupled electrical, acoustical (fluidic) and mechanical interactions inside the cochlea that enable sound processing. A positive feedback mechanism within the cochlea, called the cochlear amplifier, provides amplitude and frequency selectivity in the mammalian auditory system. The cochlear amplifier and stability are studied using a nonlinear, micromechanical model of the Organ of Corti (OoC) coupled to the electrical potentials in the cochlear ducts. It is observed that the mechano-electrical transduction (MET) sensitivity and somatic motility of the outer hair cell (OHC), control the cochlear stability. Increasing MET sensitivity beyond a critical value, while electromechanical coupling coefficient is within a specific range, causes instability. We show that instability in this model is generated through a supercritical Hopf bifurcation. A reduced order model of the system is approximated and it is shown that the tectorial membrane (TM) transverse mode effect on the dynamics is significant while the radial mode can be simplified from the equations. The cochlear amplifier in this model exhibits good agreement with the experimental data. A comprehensive 3-dimensional model based on the cross sectional model is simulated and the results are compared. It is indicated that the global model qualitatively inherits some characteristics ofmore » the local model, but the longitudinal coupling along the cochlea shifts the stability boundary (i.e., Hopf bifurcation point) and enhances stability.« less
Authors:
 [1] ;  [1] ;  [2]
  1. Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22494511
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1703; Journal Issue: 1; Conference: 12. international workshop on the mechanics of hearing, Cape Sounio (Greece), 23-29 Jun 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLIFIERS; AMPLITUDES; BIFURCATION; FEEDBACK; HAIR; INSTABILITY; MEMBRANES; NONLINEAR PROBLEMS; SENSITIVITY; SIMULATION; SOUND WAVES; STABILITY